Strains isolated that could be considered probiotic included: Bacillus pumilus, Bacillus licheniformis, Bacillus megaterium, Lysinibacillus sp. and Enterococcus faecalis.
“These had the ability to inhibit microorganisms such as Aeromonas hydrophila, one of the most frequent pathogens in freshwater, and they could be suitable populations to colonize the intestine and promote an increase in the immune response,” said Liseth Paola Puello Caballero, from the university’s Master's Degree in Agricultural Sciences.
Probiotics are defined by the World Health Organization as “live microorganisms which when administered in adequate amounts confer a health benefit on the host”.
Balancing good and bad
According to a release from the university, the white cachama is considered the second species with the greatest productive and commercial potential in the extensive, semi-intensive and intensive inland fish farms of tropical America. The fish shows good resistance to captivity and is easily cultivated in rustic environments, since it supports high densities and low oxygen concentrations.
The strains identified may have potential use in aquaculture, since they showed sensitivity to commercial antibiotics used in aquaculture, plus resistance to high concentrations of acid and bile salts, and activity against pathogenic bacteria of fish. The potential probiotics may be formulated into encapsulated supplements or in powder (lyophilized).
Caballero also stressed that additional studies are needed to map the genome of these bacteria, and to determine the absence of factors associated with the ability to produce a disease.
Gastrointestinal samples were obtained at the Laboratory of Microbiology of Waters and Foods, where the fish were made a cut to extract the intestine, which was washed and from there the samples were seeded in different culture media to be able to isolate the microorganisms.